The invention relates to a method for determining disturbances when pouring molten metal from a container having an outlet channel and related parts. When pouring molten metal, disturbances occur primarily in the form of a vortex, the discharge of slag, blockages in the outlet channel and/or due to defective, refractory material forming the outlet channel.
In known methods (see, for example, the method disclosed in WO-A1 86/02583), in particular to detect slag in molten steel, voltages that are evaluated frequency-selectively are provided by means of a transmitting and receiving coil enclosing the stream of molten metal without contacting the same. The distribution of conductivity over the cross section of flow is detected and from such information the proportion of slag in the flowing molten metal is determined from a frequency analysis of voltages corresponding to said distribution. In addition to this, measurements of the changing temperature of the molten metal are used in conjunction with measured values of the induced voltage spectrum. Since said transmitting and receiving coils are subject to intensive heat, on the one hand they wear relatively rapidly, and, on the other hand, incidents that disturb normal operation cannot be ruled out. In addition to this, this method of measurement is time-consuming and, therefore, is also not reliable.